This enables the slime-fancy contribs for slime, and no longer enables
rainbow-delimiters for the slime repl.
rainbow-delimiters doesn't seem to work with the slime-repl anyway, and
messes up all of the other colors.
In `prelude-common-lisp.el`, look in both `~/quicklisp/` and
`~/.quicklisp/` for `slime-helper.el`, on the assumption that most users
will have Quicklisp installed in one of these two locations.
This commit fixes#582
The paredit backspace override without having paredit-backward-delete-key defined by paredit was breaking slime loading. I commented this out rather than deleting it since I noticed you had just commented out other paredit stuff elsewhere